Flexible metal hoses have a variety of uses but one of the primary applications is in automotivre vehicles, particularly trucks, where the flexible metal hoses are assembled between an engine exhaut duct or pipe connected to the vehicle engine and an exhaust duct pipe attached to the chassis or vehicle of the body.
In the past flexible metal hoses have been welded in place between spaced ducts or pipes in engine exhaust systems. However, the welded constructions were not always satisfactory because the welding operation was frequently difficult and inconvenient to perform during the vehicle assembly, and when the union between the duct and flexible hose failed, removal and replacement of the flexible hose was a difficult and time-consuming task.
Accordingly, the prior art proposed various clamping arrangements by which respective ends of the flexible metal hose were secured to exhaust system pipes. In some proposals the hose and pipes were telescoped together and clamped by a U-shaped bolt and a cooperating block. These connections were not fluid-tight because the hose and pipe were slightly flattened and exhaust gas leaked between them to the atmosphere.
In other proposals the hose ends were aligned axially with exhaust duct system pipes and secured by a clamping arrangement which surrounded the union and clamped both the hose end and the duct pipe end in juxtaposition. These clamping assemblies were normally constructed from a tubular body which could be drawn tightly about both the duct pipe and the metal hose end to firmly secure the clamp to each of them. The clamp was normally provided with a seal to prevent the escape of exhaust gas between the adjacent ends of the pipe and hose and through the clamp. Since the duct pipe and hose were frequently of different diameters the clamp also had to be constructed so that adequate clamping and sealing forces could be applied.
While the prior art clamping assemblies tended to reduced the problems associated with repair and replacement of exhaust system components, the assembly of the flexible metal hose to the respective duct pipes was difficult and the clamps themselves were of multi-part relatively costly construction. Still further, these clamps were sometimes subject to loosening over time because of vibrations encountered during operation of the vehicle.